# US 10,557,872 B2 · Measuring arrangement and method for contactless electric current measurement > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,557,872 B2 - Document ID: US10557872B2 - Status: Granted - Kind: B2 - Application number: 15/196,520 - Filed: 2016-06-29 - Published: 2017-01-05 - Granted: 2020-02-11 - Earliest claimed: 2015-06-30 - Assignees: Testo AG - Applicants: Testo AG - Inventors: Dirk Gopfert; Nebojsa Nesovic; Jorg Volger - Web page: https://patentgrep.com/patent/US10557872B2 ## CPC - G01R 15/181: {using coils without a magnetic core, e.g. Rogowski coils} - G01R 15/18: using inductive devices, e.g. transformers - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) ## Abstract In a measuring arrangement (1) for contactless electric current measurement, it is provided to detect a common signal of a measuring coil arrangement (2) and a compensating coil arrangement (3) by a first detection device (4) and to detect a signal from at least one measuring coil (6, 7) of the measuring coil arrangement (2) separately therefrom by a second detection device (5, 23). ## Claims ### Claim 1 A measuring arrangement (1) for contactless electric current measurement, comprising: a measuring coil arrangement (2) having a first measuring coil (6) and a second measuring coil (7), a compensating coil arrangement (3) having a first compensating coil (11) connected to one end of the first measuring coil (6) and a second compensating coil (13) connected to one end of the second measuring coil (7), a first detection device (4) that detects common signals from the first and second measuring coils (6, 7) of the measuring coil arrangement (2) and the first and second compensating coils (11, 13) of the compensating coil arrangement (3), a second detection device (5) that separately detects a signal of the first measuring coil (6) of the measuring coil arrangement (2), an electric conductor receptacle (8), the first and second measuring coils are located on mutually opposite sides (35, 36) of the electric conductor receptacle (8), and the compensating coil arrangement (3) having a third compensating coil (12) and a fourth compensating coil (14), wherein the third compensating coil (12) being connected to an other end of the first measuring coil (6) from the first compensating coil (11), and the fourth compensating coil (14) being connected to an other end of the second measuring coil (7) from the second compensating coil (12). ### Claim 2 (depends on 1) The measuring arrangement (1) for contactless electric current measurement as claimed in claim 1, wherein the compensating coils (11, 12, 13, 14) assigned to each of the measuring coils (6, 7) include compensating coil axes and are aligned at an angle of between 45° and 135° in relation to axes of respective ones of the first and second measuring coils (6, 7). ### Claim 3 (depends on 1) The measuring arrangement (1) for contactless electric current measurement as claimed in claim 1, wherein the first detection device (4) and the second detection device (5) each have an amplification member (19, 20). ### Claim 4 (depends on 1) The measuring arrangement (1) for contactless electric current measurement as claimed in claim 1, further comprising a digital signal processing device (19, 20) connected in each case to the first detection device (4) and the second detection device (5). ### Claim 5 (depends on 1) The measuring arrangement (1) for contactless electric current measurement as claimed in claim 1, wherein the compensating coils (11, 12, 13, 14) of the compensating coil arrangement (3) have at least one of substantially identical cross sections, winding densities or number of turns. ### Claim 6 (depends on 1) The measuring arrangement (1) for contactless electric current measurement as claimed in claim 1, wherein the measuring coils (6, 7) of the measuring coil arrangement (2) have at least one of substantially identical cross sections, winding densities or number of turns. ### Claim 7 (depends on 1) The measuring arrangement (1) for contactless electric current measurement as claimed in claim 1, wherein a number of turns of at least one measuring coil (6, 7) of the measuring coil arrangement (2) is greater than a number of turns of at least one assigned compensating coil (11, 12, 13, 14) of the compensating coil arrangement. ### Claim 8 (depends on 1) The measuring arrangement (1) for contactless electric current measurement as claimed in claim 1, wherein the measuring coils (6, 7) and the compensating coils (11, 12, 13, 14) are arranged in a mesh (28) connected to the first detection device (4). ### Claim 9 (depends on 1) The measuring arrangement (1) for contactless electric current measurement as claimed in claim 1, wherein winding directions of the measuring coils (6, 7) and of the compensating coils (11, 12, 13, 14) correspond. ### Claim 10 (depends on 1) The measuring arrangement (1) for contactless electric current measurement as claimed in claim 1, wherein at least one of the measuring coils (6, 7) or the compensating coils (11, 12, 13, 14) are embodied as air coils. ### Claim 11 (depends on 1) The measuring arrangement (1) for contactless electric current measurement as claimed in claim 1, wherein at least one of the measuring coil arrangement (2) or the compensating coil arrangement (3) define at least one of a fork-shaped or rigid electric conductor receptacle (8) for an electric conductor to be measured. ### Claim 12 (depends on 11) The measuring arrangement (1) for contactless electric current measurement as claimed in claim 11, wherein at least one of the measuring coil arrangement (2) or the compensating coil arrangement (3) are arranged in a spatially mirror-symmetric manner, and the measuring coil arrangement (2) and the compensating coil arrangement (3) are matched such that a sum of magnetic flux in the measuring coils (6, 7) and in the compensating coils (11, 12, 13, 14) equals zero for the electric conductor lying outside of the electric conductor receptacle (8). ### Claim 13 (depends on 1) The measuring arrangement (1) for contactless electric current measurement as claimed in claim 1, further comprising a measuring error recognition device (31) configured to compare, firstly, signals from at least one of the first measuring coil (6) or the second measuring coil (7) with, secondly, the common signal of the measuring coil arrangement (2) and the compensating coil arrangement (3), and to output a measuring error notification if the common signal is less than the signal from at least one of the first measuring coil (6) or the second measuring coil (7). ### Claim 14 (depends on 1) The measuring arrangement (1) for contactless electric current measurement as claimed in claim 1, further comprising an activation apparatus (32) configured to detect a signal of at least one of the measuring coil arrangement (2) or of the compensating coil arrangement (3) and to activate a further component for at least one of processing or outputting a measured value of the measuring coil arrangement (2) if the signal satisfies a stored criterion. ### Claim 15 (depends on 1) The measuring arrangement (1) for contactless electric current measurement as claimed in claim 1, further comprising a measuring range switching device (33) configured to switch from processing the common signal of the measuring coil arrangement (2) and the compensating coil arrangement (3) to only processing the signal from the measuring coil arrangement (2) when the signal exceeds a threshold. ### Claim 16 A measuring arrangement (1) for contactless electric current measurement, comprising: a measuring coil arrangement (2) having a first measuring coil (6) and a second measuring coil (7), a compensating coil arrangement (3) having a first compensating coil (11) connected to one end of the first measuring coil (6) and a second compensating coil (13) connected to one end of the second measuring coil (7), a first detection device (4) that detects common signals from the first and second measuring coils (6, 7) of the measuring coil arrangement (2) and the first and second compensating coils (11, 13) of the compensating coil arrangement (3), a second detection device (5) that separately detects a signal of the first measuring coil (6) of the measuring coil arrangement (2), an electric conductor receptacle (8), the first and second measuring coils are located on mutually opposite sides (35, 36) of the electric conductor receptacle (8), and a third detection device (23), wherein a signal of the first measuring coil (6) of the measuring coil arrangement (2) is detectable by the second detection device (5) and a signal of the second measuring coil (7) of the measuring coil arrangement (2) is detectable by the third detection device (23).